Perpetual motion machines – identifying the violated law Evaluate the statement: “A machine that violates the first law of thermodynamics is called a perpetual motion machine of the second kind.”

Introduction / Context:
The terminology of perpetual motion machines (PMMs) distinguishes between violations of the first and second laws of thermodynamics. This question checks whether you can correctly associate the violated principle with the PMM “kind.”

Given Data / Assumptions:

• First law: conservation of energy.
• Second law: directionality/entropy, impossibility of perfect conversion or spontaneous cold-to-hot transfer.
• PMM terminology is standard in thermodynamics texts.

Concept / Approach:
A perpetual motion machine of the first kind (PMM1) violates the first law by creating energy from nothing or delivering net work without energy input. A perpetual motion machine of the second kind (PMM2) respects energy conservation but violates the second law, for example by converting all heat from a single reservoir to work or transferring heat from cold to hot with no other effect.

Step-by-Step Solution:
Identify the claimed violation: first law (energy conservation).Recall definitions: PMM1 ↔ first-law violation; PMM2 ↔ second-law violation.Therefore, labeling a first-law violator as a PMM2 is incorrect.

Verification / Alternative check:
Classic examples of PMM2 include Kelvin–Planck and Clausius violations (100% heat-to-work engines; spontaneous cold-to-hot transfer). None of these create energy; they contravene entropy-based limitations.

Why Other Options Are Wrong:

• “Correct” and conditional variants misclassify the violation.
• System type (open/closed) and scale (microscopic) do not change the law being violated.

Common Pitfalls:
Confusing “perpetual motion” generically with the specific PMM1 vs. PMM2 classification. Always tie PMM1 to energy creation and PMM2 to second-law violations.

Final Answer:
Incorrect